Which of the following is true if nnn is prime?
ϕ(n)=n−1\phi(n) = n-1ϕ(n)=n−1
Every a∈{1,…,n−1}a \in \{1, \dots, n-1\}a∈{1,…,n−1} has an inverse
(n−1)!≡−1(modn)(n-1)! \equiv -1 \pmod n(n−1)!≡−1(modn)
All of the above